İnceltilmiş Uçlu Önüretimli Aşık Kirişlerinin Yük Taşıma Kapasitelerinin Deneysel ve Numerik Olarak İrdelenmesi ve Çözüm Önerileri

2023

Buildings

A new type of assembled concrete beam–column joint based on a bolted connection was proposed, aiming to complete the post-earthquake node repair work by replacing precast beams and bolts. To study the seismic performance of the new beam–column joints, two full-scale components of the new joints were fabricated and subjected to low cyclic loading. The whole process from crack generation to component failure was investigated in detail, and seismic performance indicators such as the hysteresis curve, skeleton curve and stiffness degradation curve were compared and analyzed. Based on the experimental results, ABAQUS finite element software was applied to numerically simulate cast-in-place joints and test joints. Based on the failure mechanism of the new assembled beam–column semi-rigid joints, a stress analysis of semi-rigid joints was carried out. The research results show that the two new joints have good seismic performance and energy dissipation performance. Bolts and precast beams are the main stress components, and the repair of new joints can be completed by replacing bolts, which meets the seismic design concepts of “strong columns and weak beams” and “strong joints and weak components”. The larger the diameter of the bolts, the higher the load capacity and the lower the stiffness degradation rate. The finite element simulation results are high-accuracy and can well reflect the seismic performance of the components. It is found that cast-in-place joints are better in energy dissipation capacity than test joints, but the ultimate bearing capacity of test joints is better than that of cast-in-place joints. Based on the experimental stress characteristics of the nodal core zone, a mechanical analysis model of the nodal core zone of the new assembled concrete beam–column joints is proposed, and shear force calculation equations for the core zone of the new assembled concrete beam–column rigid joints and semi-rigid joints are derived.

Section: Finite Element Simulation Analysismentioning

confidence: 99%

Experimental and Numerical Studies on the Seismic Performance of New Assembled Concrete Frame Beam–Column Joints

2023

Buildings

“…In the case of uniaxial tension, the stress-strain falls in the linear elastic range in the initial phase, reaching the failure stress t0  implies microscopic cracking within the concrete, after which the strain increases rapidly and the concrete constitutive follows a softening stress-strain response to represent it. At present, many scholars have done in-depth research on the equation of the compressive stress-strain curve [38][39][40][41]. China's concrete structure design code [25] compressive stress-strain equation was obtained based on many tests after verification, with a deep theoretical foundation and extensive verification.…”

Section: Numerical Simulationmentioning

confidence: 99%

“…where α c is the parameter value of the falling phase of the concrete uniaxial compressive stress-strain curve, calculated according to Equation ( 6); f cr is the representative value of the concrete uniaxial compressive strength, taken as f ck ; ε cr is the peak compressive strain corresponding to the concrete uniaxial compressive strength f cr , calculated according to Equation ( 7); d c is the concrete uniaxial compressive damage evolution parameter. Stressstrain and damage parameter-strain relationships for compression and tension are cited from the literature [41,42].…”

Section: Numerical Simulationmentioning

confidence: 99%

Study on the Mechanical Performance of H-Shaped Steel-Concrete Laminated Plate Composite Beams under Negative Bending Moment

Ding

2022

Sustainability

To make the construction of assembled steel-reinforced truss concrete laminated plate composite structure faster, safer, and more efficient, this paper proposes an H-shaped steel-reinforced truss concrete laminated plate composite structure with new angle connectors embedded in the precast bottom panel. Through experimental studies on the H-shaped steel-concrete laminated plate composite beams with precast bottom panels protruding from the bent-up bars, precast bottom panels with embedded new angle connectors and laminated whole cast slab, the similarities and differences of load-deflection, deflection distribution, interface slip, crack distribution and cross-section strain distribution of three groups of composite beams under negative bending moment were analyzed and compared. Using ABAQUS finite element software, we established a finite element model and found the numerical simulation results were in good agreement with the experimental results. Based on this, six groups of finite element models were established for parametric analysis to investigate the effect of concrete strength on the flexural load capacity and flexural stiffness of the steel-laminated plate composite beams with embedded angle connectors. The results of the study show that the combined performance of the H-shaped steel-concrete laminated plate composite beams with the new angle connection embedded in the precast bottom panel was better and the flexural stiffness was greater. The slippage of the H-shaped steel-concrete laminated plate composite beams with embedded new angle connectors in the precast bottom panel was less than the slippage of the precast bottom slab bent-up bars protruding and the laminated cast plate, with the maximum slippage being only 1/2 of the precast bottom panel bent-up bars protruding. In the composite structure of H-shaped steel-concrete composite slabs under negative bending moment, shear angle connectors can replace the bent-up bars protruding from the laminated bottom panel to achieve without extending the reinforcement of the laminated bottom panel.

“…With factory production, fabricated construction and digitized management, the prefabricated building is considered to be an effective way to realize the intelligent operation of the whole life cycle of buildings and green development of urban and rural construction (Tam et al ., 2015; Arashpour et al ., 2018; Ji et al ., 2020; Wuni and Shen, 2020; Huang et al ., 2022). It is becoming an important trend to replace the traditional cast-in-place building in the construction industry worldwide (Tumminia et al ., 2018; El-Abidi et al ., 2019; Sabet and Chong, 2020; Aksoylu et al ., 2021; Qi et al ., 2023; Vasishta et al ., 2023). As plant production and transportation of precast components are two distinctive characteristics of prefabricated building, which is not found in traditional cast-in-situ construction, it is necessary to improve the management of component production and transportation (Fang and Ng, 2019; Kim et al ., 2020; Wang et al ., 2020; Du et al ., 2022; Xiong et al ., 2022).…”

Section: Introductionmentioning

confidence: 99%

Integrated scheduling optimization of production and transportation for precast component with delivery time window

Dan

2023

ECAM

PurposeProduction and transportation of precast components, as two continuous service stages of a precast plant, play an important role in meeting customer needs and controlling costs. However, there is still a lack of production and transportation scheduling methods that comprehensively consider delivery timeliness and transportation economy. This article aims to study the integrated scheduling optimization problem of in-plant flowshop production and off-plant transportation under the consideration of practical constraints of customer order delivery time window, and seek an optimal scheduling method that balances delivery timeliness and transportation economy.Design/methodology/approachIn this study, an integrated scheduling optimization model of flowshop production and transportation for precast components with delivery time windows is established, which describes the relationship between production and transportation and handles transportation constraints under the premise of balancing delivery timeliness and transportation economy. Then a genetic algorithm is designed to solve this model. It realizes the integrated scheduling of production and transportation through double-layer chromosome coding. A program is designed to realize the solution process. Finally, the validity of the model is proved by the calculation of actual enterprise data.FindingsThe optimized scheduling scheme can not only meet the on-time delivery, but also improve the truck loading rate and reduce the total cost, composed of early cost in plant, delivery penalty cost and transportation cost. In the model validation, the optimal scheduling scheme uses one less truck than the traditional EDD scheme (saving 20% of the transportation cost), and the total cost can be saved by 17.22%.Originality/valueThis study clarifies the relationship between the production and transportation of precast components and establishes the integrated scheduling optimization model and its solution algorithm. Different from previous studies, the proposed optimization model can balance the timeliness and economy of production and transportation for precast components.